Search PubMed⌕ Search

Biomedical subjects

Eric Fontaine

Publications and source records attributed to Eric Fontaine.

24 records · Page 2Linked to original sources
PubMed2002

Thyroid status is a key regulator of both flux and efficiency of oxidative phosphorylation in rat hepatocytes.

Thyroid status is crucial in energy homeostasis, but despite extensive studies the actual mechanism by which it regulates mitochondrial respiration and ATP synthesis is still unclear. We studied oxidative phosphorylation in both intact liver cells and isolated mitochondria from in vivo models of severe not life threatening hyper- and hypothyroidism. Thyroid status correlated with cellular and mitochondrial oxygen consumption rates as well as with maximal mitochondrial ATP production. Addition of a protonophoric uncoupler, 2,4-dinitrophenol, to hepatocytes did not mimic the cellular energetic change linked to hyperthyroidism. Mitochondrial content of cytochrome oxidase, ATP synthase, phosphate and adenine nucleotide carriers were increased in hyperthyroidism and decreased in hypothyroidism as compared to controls. As a result of these complex changes, the maximal rate of ATP synthesis increased in hyperthyroidism despite a decrease in ATP/O ratio, while in hypothyroidism ATP/O ratio increased but did not compensate for the flux limitation of oxidative phosphorylation. We conclude that energy homeostasis depends on a compromise between rate and efficiency, which is mainly regulated by thyroid hormones.

Adenosine Triphosphate↗
PubMed2002

Endocervicosis of the urinary bladder. Immunohistochemical comparative study between a new case and normal uterine endocervices.

Endocervicosis of the urinary bladder is a rare non-neoplastic condition characterized by endocervical-type glands deeply situated in the urinary bladder wall of women of reproductive age. We compared the immunohistochemical phenotype of a case of endocervicosis in a 35-year-old woman with four normal uterine endocervices. We tested antibodies known as reactive in the uterus and not mentioned or negative in the urothelium (HBME-1, estrogen receptor (ER), progesterone receptors (PR), DF3, Chromogranin). The proliferative index was assessed with MIB-1 antibody. Endocervicosis glands displayed stronger expression of HBME-1, ER and PR than normal endocervices, while the urothelium was negative. There was no difference in DF3 expression. The number of Chromogranin-positive cells was higher in endocervicosis than in the endocervices. The proliferative index was higher in the endocervicosis glands (15%) than in the normal endocervices (mean 3%), but was within the normal range established for endocervical glands. Our results confirm the endocervical nature of endocervicosis and constitute further arguments for the mullerian origin hypothesis. The only modestly increased proliferative index, as compared to endocervical malignancies, is consistent with a benign diagnosis.

Adult↗
PubMed2002

Regulation of the mitochondrial permeability transition pore by ubiquinone analogs. A progress report.

The permeability transition pore (PTP) is a mitochondrial inner membrane Ca2+-sensitive channel that plays a key role in different models of cell death. In a series of recent studies we have shown that the PTP is modulated by quinones, and we have identified three functional classes: (i) PTP inhibitors; (ii) PTP inducers; and (iii) PTP-inactive quinones that compete with both inhibitors and inducers. Here, we review our current understanding of pore regulation by quinones, and present the results obtained with a new series of structural variants. Based on the effects of the compounds studied so far, we confirm that minor structural changes profoundly modify the effects of quinones on the PTP. On the other hand, quinones with very different structural features may have qualitatively similar effects on the PTP. Taken together, these results support our original proposal that quinones affect the PTP through a common binding site whose occupancy modulates its open-closed transitions, possibly through secondary changes of the Ca2+-binding affinity.

Animals↗
PubMed2002

[Extracorporeal lithotripsy in children. Report of 30 cases].

OBJECTIVE: To evaluate the efficacy of extracorporeal lithotripsy in the treatment of urinary stones in children. MATERIAL AND METHOD: Thirty children (19 boys, 11 girls) with a mean age of 7 years (range: 14 months to 17 years) with a total of 32 urinary stones were treated by extracorporeal lithotripsy. The stone was situated in the kidney in 27 cases, the lumbar ureter in 4 cases and the pelvic ureter in 1 case. 19 patients had single stones, 9 patients had multiple pyelocaliceal stones and 3 had staghorn calculi. RESULTS: General anaesthesia was performed in 2/3 of cases (age < 10 years). The mean number of treatment sessions was 1.3. The success rate (absence of residual fragments) was 77%, while residual fragments < or = 3 mm persisted in 4 cases. There were 3 failures. Complications occurred in 3 cases: ureteric obstruction (2), anuria (1) requiring complementary treatment: double J stent (1), nephrostomy (1), incision of ureterocele (1). CONCLUSION: Extracorporeal lithotripsy is effective in children and must be considered as first-line treatment for urinary stones in children. The only contraindication is untreated obstructive uropathy.

Adolescent↗
PubMed2002

[Treatment of phimosis with locally applied 0.05% clobetasol propionate. Prospective study with 108 children].

OBJECTIVE: This study was designed to evaluate the efficacy of topical application of corticosteroid cream in the treatment of phimosis in children and to compare the results obtained with those reported in the literature. MATERIALS AND METHODS: In the context of a prospective study conducted between January 1997 and November 2001, 108 children with a mean age of 5.9 years, presenting with true phimosis preventing retraction of the foreskin, were treated by twice-daily application of 0.05% clobetasol propionate cream for 10 days. The results were evaluated at one month and then every six months by a urologist in the outpatients department. A second course of treatment identical to the first was proposed in the case of failure or partial efficacy. RESULTS: 96 children were evaluated with a mean follow-up of 14 months (range: 6 to 24 months). Seventy nine children (82%) are cured after a first course of treatment. In the remaining 17 children, 2 were treated by circumcision and 15 received a second course of treatment resulting in cure in another 9 cases. The final cure rate was therefore 92%. Among the six failures, 4 children were circumcised, corresponding to a total of 6 circumcisions out of this series of 96 cases of phimosis (6%). No local or systemic adverse effects related to steroid therapy were observed and no recurrence of phimosis was observed during the study. CONCLUSION: This study confirms the efficacy and safety of local steroid therapy in the treatment of phimosis in children. Surgical treatment of phimosis should therefore be reserved for failures of medical treatment and has now become much less frequent.

Administration, Topical↗